Method and installation for emptying casks

ABSTRACT

The invention concerns an installation for emptying casks ( 1 ) equipped with an external bag ( 11 ) and an internal bag ( 12 ) containing powdery products. It comprises a glove box ( 12 ) consisting of a bell made of a transparent material. It is provided, on its upper part, with an opening for the passage of a suction rod ( 3, 31, 32 ) equipped with sealing means between said pipe and the bell. The lower part of the bell is provided with means adapted to be urged in sealed position on the upper part of a cask ( 1 ). The bell ( 2 ) is suspended to a frame ( 5, 15 ) for its vertical displacement.

BACKGROUND OF THE INVENTION

The present invention relates to an installation for emptying casksequipped with a double internal bag comprising an outer bag and an innerbag containing powdery products and to a method for using saidinstallation.

PRIOR ART

For the chemical industry, and more particularly the pharmaceuticalindustry, the confinement of products has always been a fundamentalproblem. During the last ten years, the products used by this industry,in particular powdery products, have been constantly increasing in theirtoxicity and in their reactivity. Furthermore, the production standardsrelating to quality result in the confinement of such products beingunavoidable.

Confinement is also a necessity for both ecological reasons and forprotecting the health of operators and, furthermore, to prevent theproduct from coming into contact with the ambient atmosphere and beingcontaminated. The operators have, up until the present time, beenprotected by clothing and gas masks or similar apparatuses. However,this solution is not satisfactory because is makes manipulationsdifficult and unpleasant. Furthermore, this solution protects neitherthe products nor the environment: it is therefore necessary to make useof more sophisticated systems. In such systems, complex ventilation andfiltration systems are often resorted to. Installations comprising gloveboxes have been used. A glove box is a closed enclosure provided withopenings leading to the inside of gloves through which the operators tryto manipulate the product that are inside a cubicle, for example bytaking a cask, emptying it into another device for the manufacture of aproduct or for transferring it by means of an appropriate installationto a precise place. This type of installation is extremely costly andthe manipulations of the casks is rather difficult using installationswith gloves which, of course, make satisfactory confinement possible.This type of installation, called an isolating installation is notnecessarily the best solution particularly when the powder must beloaded into an item of equipment such as, for example, a reactor, adryer, etc, whose accessibility is poor and it is difficult to placesuch an isolating installation above the apparatus or the machine.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose an installationcombining the advantages of a glove box and a powder transfer system inorder to carry out such operations whilst ensuring the confinement ofthe product and also the protection of the operator and of theenvironment.

The invention also relates to a method of using this installation.

The installation for emptying casks according to the invention ischaracterized by the characterizing clause of claim 1.

The advantage of the installation according to the invention is the factthat, on the one hand, it is easy to place a glove box, which hasalready proved itself, on a cask provided with two internal bags, one ofwhich is outside the other, to use a suction rod for sucking up theproduct and, consequently and still by manipulating through the glovebox, to put another cask in place of the first one and to use it in avery flexible manner.

According to a variant embodiment, the lower part of the bell comprisesa flat surface fitted on its lower face with a flat seal making itpossible, during the positioning of the glove box on the cask, to ensurethe sealing between the two of them, said flat surface being providedwith an annular opening formed from a holding ring provided with meansof holding the upper part of the bags.

The method according to the invention is defined in claim 6.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail with reference to theappended drawings.

FIG. 1 is a diagrammatic side view of the installation according to theinvention.

FIG. 2 is an enlarged view of the bell placed on a cask.

FIGS. 3-13 are partial views of the installation illustrating the stagesof the method.

FIG. 14 is a plan view of the bell.

FIG. 15 is a cross-sectional view of two filters.

FIG. 16 is a diagrammatic view of the cleaning device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a cask containing the powdery product to be emptied, thebell 2, the suction rod 3 and a support chassis 5.

The cask 1 comprises, inside of it, two bags 11 and 12, in principlemade of a plastic material, each one closed independently: the bag 11will be called the outer bag and the bag 12 will be called the innerbag. These two bags make it possible to confine the powdery product evenafter opening the cask, that is to say after having removed its lid. Theglove box 2 is fixed to a support 51 of the chassis 5 which can bedisplaced in the vertical direction. The suction rod 3 is suspended by aflexible link 52 and a pulley 53 from the chassis 5 in order to allowthe withdrawal of the rod or its insertion during the various stages ofthe method. The chassis 5 has a flat surface provided with rollers 54facilitating the displacement of the casks and in particular theirpositioning under the glove box 2.

The suction rod essentially comprises a pipe 31 connected to a suctiondevice making it possible to transfer the product from the cask toanother reservoir or directly into the reactor or device in which theproduct must be used. The pipe 31 is surrounded by a flexible sleeve 32closed at its upper end and being connected in a sealed manner to theupper part of the glove box 2, as will be seen below, thus making itpossible to ensure the sealing of the installation.

Reference will now be made to FIG. 2 in order to describe the glove boxin detail. The glove box comprises a bell-shaped part 21 made of atransparent material, for example acrylic glass, through which theoperator can see and monitor the emptying operations. It is alsopossible to have a bell made of stainless steel fitted with a part madeof transparent material to make it possible to see inside the bellduring its use. Two openings 22 placed on the side surface of the bellmake it possible to install gloves fitted in a sealed manner into theseopenings which allow the manipulation of the various items inside thebell. The upper part of the bell is provided with an opening 26 throughwhich passes the suction rod 3 and, in particular, the pipe 31, whilethe flexible sleeve 32 is fixed in a sealed manner onto the upper partof the opening 26. It is possible, in an optional manner, to providethis opening with a valve 27 in order to be able to close it when therod, and in particular the pipe 31, are in a separated position such asshown for example in FIG. 1 or 2. The lower part of the glove box has aholding ring made of stainless steel 24 forming an annular opening onthe lower part of the bell 23 which is flat. The flat surface 23 isprovided with a flat seal via which it is placed on the upper part ofthe cask. The radial width of this flat surface makes it possible toadapt the glove box to casks whose diameters may be different, theessential point being that the bell can stand on the upper edge of thecask via the flat seal thus ensuring sealing. The ring 24 is providedwith one or two retaining rings 25 which will be used for holding, aswill be explained below, the two bags 11, 12 located inside the cask 1.The glove box is provided with a fixing device 28 by means of which thisglove box is connected to the vertical displacement device 51 of thechassis 5.

The method of using this installation will now be described withreference to FIGS. 3 to 13. The operator starts by removing the lid fromthe cask 1, opening the outer bag 11 and slipping a disposable sealingring 6 (FIG. 4) inside. The sealing ring 6 is positioned inside theholding ring 24 and the outer bag 11 is opened (FIG. 5) by removing theflexible tie. Up until this stage, no contact with the product locatedinside the cask is possible since the inner bag 12 is still closed.Subsequently, the glove box 2 is lowered onto the cask, as shown in FIG.6, and the operator places his hands in the gloves of the glove box inorder to remove the upper part of the bag 11′ that remained during theemptying of the preceding cask and to throw it through an opening 29 ofthe bell and into a sack. In order to continue, the upper edge of theouter bag 11 is fixed to the holding ring 24 by means of an O-ring (FIG.2). Then he opens the second bag 12 (FIG. 7) and he throws the flexibletie through the opening 29 and ensures that the upper part is also heldover the holding ring 24 with the same O-ring or with a second one. Fromthis moment, the product can be sucked up, which is carried out bylowering the suction rod (FIG. 8) and by guiding it inside the cask inorder to be able to suck up the product from the smallest recesses to befound inside. The operator, during this phase, manipulates the suctionrod without being in contact with the product which is confined insidethe glove box-cask installation and without wearing special clothing orequipment.

When the cask is completely empty (FIG. 9), the rod 3 is raised and theoperator inserts his hands in the glove box (FIG. 10) and releases theupper part of the inner bag 12 which falls inside the outer bag 11together with the disposable ring 6. Then the suction rod and glove boxassembly (FIG. 11) is raised up to a certain height making it possibleto have access to the upper part of the outer bag 11. Using two ties(FIG. 12), the upper part of the bag 11 is tied at two places separatedin the vertical direction and the bag is then cut between the two ties(FIGS. 12 and 13), which makes it possible for the lower part of the bag11, which is closed, to drop inside the empty cask while the upper partof the bag 11, also closed and isolated, remains on the ring 24. Noleakage of the product is able to contaminate either the operator or theenvironment of the installation.

Subsequently, the empty cask is taken away and a new cask is brought inand the same operations as before (FIG. 2 onwards) are started again.

When the product to be transferred contains solvent or when it can reacton contact with air or with moisture, the installation can be placed ina nitrogen atmosphere.

In order to ensure that work is carried out inside the installationunder a slight depression, the bell 2 (FIG. 14) is provided with twoopenings on the side surface provided with two smooth tubes 7, 8. Eachtube is provided with a filter 71, 72 fitted in a sealed manner. Bymeans of a ventilation circuit, a flow of air (or of nitrogen ifappropriate) is provided between the two filters in order to create aslight depression inside of the installation and to avoid any leakage ofthe product in the event of a manipulation error or another problem.These filters 71, 72 are standard filtering cartridges of the “pushthrough” type, that is to say it suffices to push the new cartridge ontothe old one in order to position it, the old one falling into the glovebox so that it can be removed through the opening 29. FIG. 15 partiallyillustrates the flow of air (or of nitrogen) through the filters 71, 72.

Finally, FIG. 16 is a diagrammatic representation of a system forcleaning the installation, that is to say the bell and the rod. There ispositioned a cask 8 provided with an inlet 81 for the cleaning liquidfollowed by a hose 82 whose end carries a spray gun 83. The cask 8comprises a drainage opening 84. The bell is placed on the cask 8, theducts of the two filters are closed and cleaning is carried out byspraying. To clean the rod 3, the cleaning liquid is made to flowbetween the cover 32 and the pipe 31. After the cleaning, the liquid isdrained into a pit or a suitable container.

The installation described is very flexible as it can be moved and usedwith different equipment. Furthermore, it is possible to install it on aweighing device thus making it possible to check the quantity of productsucked up.

The glove box can easily be adapted to different diameters, or evendifferent cask geometries by changing the face 23.

Depending on the product to be transferred, it is possible to carry outthe transfer in an inert atmosphere.

Although illustrative embodiments of the invention have been shown anddescribed, a wide range of modification, change and substitution iscontemplated in the foregoing disclosure and in some instances, somefeatures of the present invention may be employed without acorresponding use of the other features. Accordingly, it is appropriatethat the appended claims be construed broadly and in a manner consistentwith the scope of the invention.

1. An installation adapted for emptying casks equipped with a doubleinternal bag comprising an outer bag and an inner bag containing powderyproducts, the installation comprising a glove box comprised essentiallyof a bell at least partially made of a transparent material and providedwith a lower, cask interface and an upper suction rod opening equippedwith a sealing device which seals between said rod and the bell, andwherein the lower cask interface is provided with sealing interfaceadapted for interfacing with an upper part of a cask in a sealed mannerand wherein a retaining device holds upper parts of the outer and innerbags, after they have been opened, against the lower cask interface. 2.The installation as claimed in claim 1, wherein the lower cask interfacecomprises a flat surface provided with a flat seal fitted thereto inorder to ensure sealing with the cask prior to being processed, saidflat surface being provided with an annular opening formed from aholding ring provided with the retaining device.
 3. The installation asclaimed in claim 1 wherein the glove box and the suction rod are mountedon a chassis designed to be able to raise and lower the glove box andsuction rod assembly above a cask to be processed.
 4. The installationas claimed in claim 1, wherein the glove box is provided with afiltering device making it possible to keep the installation under avacuum.
 5. The installation as claimed in claim 4, wherein the filteringdevice comprises two openings on a side surface of the bell, theopenings being provided with two smooth tubes in which a filter isfitted in a sealed manner and wherein further, the two tubes areconnected to an air circulation system.
 6. The installation as claimedin claim 1, wherein it comprises a system for cleaning the bellcomprising a cask provided on its upper part with an inlet for thecleaning liquid into a hose fitted with a spray gun.
 7. The installationas claimed in claim 1, wherein the glove box is provided with an openingfor removing the waste of the bags when changing the cask.
 8. A methodof using the installation as claimed in claim 1, and which comprises thefollowing steps: the cask to be processed is opened by removing its lidand it is placed under the glove box, a disposable sealing ring isinserted in the upper part of the outer bag and it is inserted in thering of the bell, the outer bag is opened, the glove box is lowered ontothe cask until it is in sealed contact with the cask, using the glovesthe outer bag is fixed to the holding ring by means of the sealing ring,the inner bag is opened and it is also fixed to the holding ring, thehands are withdrawn from the gloves and the cask is processed using thesuction rod, when the cask is empty the gloves are used to detach theinner bag and it is allowed to drop inside the cask with the sealingring, the glove box is raised over a predetermined height while keepingthe outer bag on the holding ring and the bag is closed at two axiallyseparated places using two ties, the bag is cut between these twoplaces, the lower part of the bag is dropped into the cask with theupper part remaining on the glove box, the empty cask is removed, a newcask is brought into position and the same method is started againexcept that, before fixing the outer bag on the holding ring, theremaining part of the preceding bag is removed through the opening ofthe glove box.
 9. The method as claimed in claim 8, wherein the transferis carried out in a nitrogen atmosphere.
 10. An installation adapted foremptying casks equipped with a double internal bag comprising an outerbag and an inner bag containing powdery products, the installationcomprising a glove box comprised essentially of a bell at leastpartially made of a transparent material and provided with a lower, caskinterface and an upper suction rod opening equipped with a sealingdevice which seals between said rod and the bell, and wherein the lowercask interface is provided with means adapted for interfacing with anupper part of a cask in a sealed manner and wherein a retaining deviceholds upper parts of the outer and inner bags, after they have beenopened, against the lower cask interface, wherein the lower caskinterface comprises a flat surface provided with a flat seal fittedthereto in order to ensure sealing with the cask prior to beingprocessed, said flat surface being provided with an annular openingformed from a holding ring provided with the retaining device.
 11. Aninstallation adapted for emptying casks equipped with a double internaltag comprising an outer bag and an inner bag containing powderyproducts, the installation comprising a glove box comprised essentiallyof a bell at least partially made of a transparent material and providedwith a lower, cask interface and an upper suction rod opening equippedwith a sealing device which seals between said rod and the bell, andwherein the lower cask interface is provided with means adapted forinterfacing with an upper part of a cask in a sealed manner and whereina retaining device holds upper parts of the outer and inner bags, afterthey have been opened, against the lower cask interface, wherein theglove box and the suction rod are mounted on a chassis designed to beable to raise and lower the glove box and suction rod assembly above acask to be processed.
 12. An installation adapted for emptying casksequipped with a double internal bag comprising an outer bag and an innerbag containing powdery products, the installation comprising a glove boxcomprised essentially of a bell at least partially made of a transparentmaterial and provided with a lower, cask interface and an upper suctionrod opening equipped with a sealing device which seals between said rodand the bell, and wherein the lower cask interface is provided withmeans adapted for interfacing with an upper part of a cask in a sealedmanner and wherein a retaining device holds upper parts of the outer andinner bags, after they have been opened, against the lower caskinterface, wherein the glove box is provided with a filtering devicemaking it possible to keep the installation under a vacuum, and whereinthe filtering device comprises two openings on a side surface of thebell, the openings being provided with two smooth tubes in which afilter is fitted in a sealed manner and wherein further, the two tubesare connected to an air circulation system.
 13. A method of using aninstallation adapted for emptying casks equipped with a double internalbag comprising an outer bag and an inner bag containing powderyproducts, the installation comprising a glove box comprised essentiallyof a bell at least partially made of a transparent material and providedwith a lower, cask interface and an upper suction rod opening equippedwith a sealing device which seals between said rod and the bell, andwherein the lower cask interface is provided with means adapted forinterfacing with an upper part of a cask in a sealed manner and whereina retaining device holds upper parts of the outer and inner bags, afterthey have been opened, against the lower cask interface, the methodcomprising the following steps: opening the cask to be processed byremoving its lid and placing the cask under the glove box, inserting adisposable sealing ring in the upper part of the outer bag and in thering of the bell, opening the outer bag, lowering the glove box onto thecask until the glove box is in sealed contact with the cask, using thegloves, fixing the outer bag to the holding ring by means of the sealingring, opening the inner bag and fixing the inner bag to the holdingring, withdrawing the bands from the gloves and emptying the cask usingthe suction rod, when the cask is empty, using the gloves to detach theinner bag and allowing the inner bag to drop inside the cask with thesealing ring, raising the glove box over a predetermined height whilekeeping the outer bag on the holding ring and closing the bag at twoaxially separated places using two ties, cutting the bag between thesetwo places, dropping the lower part of the bag into the cask with theupper part remaining on the glove box, removing the empty cask, bringinga new cask into position and starting the method again except that,before fixing the outer bag on the holding ring, the remaining part ofthe preceding bag is removed through the opening of the glove box.